1. Field of the Invention
The present invention relates to a defect inspection apparatus and method using the principle of scattered light capable of suitably inspecting any haze deposited on a reticle/mask or pellicle film and more particularly to selection of an inspection area and processing of detected results.
2. Description of Related Art
Conventionally, if a pattern area or pellicle film that forms a pattern of a reticle/mask used for exposure during manufacturing of, for example, a semiconductor device, has defects, such as an adhesion of foreign matters or a haze (foreign matter vapor-deposited or crystallized), the resultant manufactured semiconductor device can suffer a lowering of the production yield. Consequently, the pattern area of the reticle/mask and the pellicle film are inspected for defects by using a defect inspection apparatus.
In recent years, since the wavelength of light emitted by an exposure machine of a stepper has become shorter, the photochemical reaction has become stronger, so that even a small amount of a gas component in the environment, such as air, tends to become as a haze on the production product. Consequently, success or failure of haze detection largely affects the yield of a semiconductor device.
Accordingly, Japanese Unexamined Patent Publication No. 1995-229844 is an example of haze inspection by visually inspecting the entire surface of a reticle/mask or pellicle film with a microscope for haze inspection to provide a pattern defect apparatus with an improved S/N ratio and thereby with high sensitivity.
However, there is still a need to provide an economically improved defect inspection apparatus to address the specific characteristics of a reticle/mask.